ABSTRACT
The delta-6-desaturase (D6D) activity was evaluated in microsomes from liver fragments of cholecystectomized subjects without any liver pathology and from explanted liver of patients affected by cirrhosis of different etiologies. We observed a significant decrease in D6D activity, evaluated by a radiochemical technique using 1-[14C]-linoleic acid as substrate, in cirrhotic patients with no correlation with the etiology of the cirrhosis. The D6D activity within the pathological group was quite similar. No alteration in the 20:4/18:2 ratio obtained by gas chromatographic analysis of fatty acid methyl esters of microsomal membranes was found. Liver disease seems to be the main cause of the decreased enzyme activity independent of its etiology.
Subject(s)
Fatty Acid Desaturases/metabolism , Microsomes, Liver/enzymology , Adult , Fatty Acids, Unsaturated/biosynthesis , Female , Humans , Linoleoyl-CoA Desaturase , Liver Cirrhosis, Alcoholic/enzymology , Liver Cirrhosis, Biliary/enzymology , Male , Middle AgedABSTRACT
The aim of this study is to assess "in vitro" the influence of polyunsaturated phosphatidylcholine on the erythrocyte membrane fluidity in alcoholics (greater than 180 g/die) and control subjects (less than 50 g/die), investigated by the evaluation of fluorescent polarization of DPH. In both groups a significant increase of membrane microviscosity was observed after incubation with 0.04 microM and 0.08 microM of PC compared to baseline values.
Subject(s)
Liver Diseases, Alcoholic/drug therapy , Phosphatidylcholines/therapeutic use , Adult , Aged , Blood Viscosity/drug effects , Erythrocyte Membrane/drug effects , Female , Humans , In Vitro Techniques , Liver Diseases, Alcoholic/blood , Male , Middle Aged , Phosphatidylcholines/administration & dosage , Phosphatidylcholines/pharmacologyABSTRACT
Data on the immune status of chronic alcoholic patients are rather conflicting probably due to the interference of liver disease and/or malnutrition on immune function. In order to avoid this kind of interference, peripheral lymphocytes from 12 chronic alcoholic patients in good nutritional status and without heavy liver damage and 15 healthy controls were examined in this study. Lymphocyte functional activity was evaluated by means of response to phytohemagglutinin, calcium ionophore A 23187, and autologous non-T-cells [autologous mixed lymphocyte reaction (AMLR)]. Phenotypical analysis was carried out by the indirect immunofluorescence technique using monoclonal antibodies specific to CD5 (mature T-lymphocytes), CD4 (helper/inducer T-lymphocytes), CD8 (suppressor/cytotoxic T-lymphocytes), glycoproteins, and an immunoglobulin fraction from rabbit directed to membrane alpha 1 acid glycoprotein (AGP) that is involved in T-cell activation process. Our results show significant impairment in AMLR while response to phytohemagglutinin, heterologous non-T-cells and carcinoma ionophore did not differ from controls. No differences were present in circulating T-lymphocytes expressing CD5, CD4, and CD8 on their membrane, whereas AGP-bearing lymphocytes were significantly lower in chronic alcoholics (14.4 +/- 8.6) than in controls (31.9 +/- 8.1; p less than 0.001). These results support the hypothesis of a direct action of alcohol on one of the pathways of lymphocyte activation and the role of the lymphocyte membrane AGP on the AMLR.
Subject(s)
Alcoholism/immunology , Blood Proteins/physiology , Glycoproteins , Immunoglobulins , Membrane Glycoproteins/physiology , T-Lymphocytes/immunology , Adult , Antigens, Differentiation, T-Lymphocyte/physiology , Female , Humans , Immune Tolerance , Lymphocyte Activation , Male , Middle AgedABSTRACT
We investigated inhibitory effect of various monoclonal antibodies on T-cell-mediated cytotoxicity against autologous hepatocytes in 24 patients with hepatitis B surface antigen/hepatitis B e antigen (HBsAg/HBeAg)-positive chronic active hepatitis. A significant reduction of cytotoxicity index occurred after preincubation of T lymphocytes with anti-Leu 7 (killer-natural killer cells), D1/12 (Ia-positive cells), 5/9 (restricted helper/inducer cells), and MLR4 ("activated" and radiosensitive helper cells) monoclonal antibodies (MAb). Anti-Leu 2a (cytotoxic/suppressor cells) and anti-Leu 3a (helper/inducer cells) MAb did not affect cytotoxic activity. This finding supports the hypothesis that the T cytotoxic reaction in this in vitro system is probably due to two mechanisms: first, spontaneous cell membrane cytotoxicity sustained by anti-Leu-7-positive lymphocytes; and second, specific cytotoxicity mediated by activated Ia-positive cells. We also found that the presence of helper/inducer cells (5/9 positive) appears to be a prerequisite for the cytotoxic reaction.
Subject(s)
Hepatitis B/immunology , Hepatitis, Chronic/immunology , Liver/immunology , T-Lymphocytes, Cytotoxic/classification , Adult , Antibodies, Monoclonal/immunology , Cytotoxicity, Immunologic , DNA Replication , Female , Hepatitis B virus/immunology , Hepatitis B virus/physiology , Humans , Male , Middle Aged , Virus ReplicationABSTRACT
Erythrocyte membrane fluidity was evaluated in chronic alcoholic patients without any liver alteration, assuming different daily ethanol amounts, and in normal subjects and related to ghost fatty acid and total lipid composition obtained by high resolution gas chromatography. Erythrocyte membrane fluidity was significantly increased in a dose dependent manner in chronic alcoholic patients respect to normal subjects. This real fluidizing effect of ethanol "in vivo" was attributed mainly to a significant increase in the polyunsaturated fatty acids amount in patient ghosts in comparison with control subjects. On the other hand the cholesterol/phospholipid ratio was not significantly affected by chronic ethanol assumption.
